In recent years, needs for enlargement of liquid crystal display panels and needs for smaller-size and portability have risen. In order to achieve these, low power consumption of a display device is required and it is necessary to apply a transparent electrode having high visible light transmittance and low resistance value.
Particularly, an organic electroluminescence (EL) device developed recently is a self-luminous type device and can be effectively applied to a small portable device, however, there are problems in which the organic EL device is a current driven device and has a large power consumption Furthermore, a plasma display panel (PDP) which is spreading in the market recently and a field emission display (FED) currently developed as a next-generation display have a problem in that they have high power consumption structures. Therefore, a low resistance-transparent conductive thin film is greatly expected.
In order to decrease the resistance value of the transparent conductive thin film, the transparent conductive thin film in which an indium tin oxide film (hereinafter referred to as ITO film) consisting of indium oxide doped with tin within a certain percentage is provided on the surface of a transparent substrate such as a glass plate or the like is proposed (for example, patent document 1).
The ITO film has superior transparency and high conductivity, however, there are problems that the content of indium in the earth crust is very low 50 ppb and the cost of raw materials increases as resources are exhausted.
In recent years, a zinc oxide material has been proposed as a low-priced material having high plasma resistance.
However, since the zinc oxide material is weak to acid or alkali, and is gradually eroded in a carbon dioxide atmosphere, particularly, application to a solar cell becomes difficult as well as application to a liquid crystal panel. Even if it is considered that the surface of the zinc oxide is treated by a coating process in order to improve the chemical resistance, adding a process for coating causes an increase in production cost.
For enlarging applicability of the transparent conductor, it is required that the transparent conductor consists of raw materials which can be stably supplied and have chemical resistance and durability in combination.
Patent Document 1: Japanese Unexamined Patent Application, First Publication 2004-095240